Liquid-absorbing core

ABSTRACT

A liquid-absorbing core which is for use in suction type drug volatilizers which comprises hydrophilic fibers and/or water-absorbing fibers. The hydrophilic fibers have an affinity for water, and are rayon, cotton, etc. Especially preferred is rayon because it has a high affinity for water. Examples of the water-absorbing fibers include water-absorbing synthetic fibers made of a polymer such as polyvinyl alcohol or polysodium acrylate and other synthetic fibers treated by, e.g., adding and adhering polyvinyl alcohol or polysodium acrylate thereto or coating them with the polymer. In the liquid-absorbing core, the hydrophilic fibers and/or water-absorbing fibers may be disposed so as to have a porosity of 10 to 80%.

TECHNICAL FIELD

[0001] The present invention relates to a liquid-absorbing core used inan absorption-type chemical agent vaporization apparatus.

BACKGROUND ART

[0002] Absorption-type chemical agent vaporization apparatuses thatabsorb chemical solutions such as aromatic substances, deodorants,insect repellents, and pesticides by means of liquid-absorbing cores,members for absorption, and diffuse them in the environment haveconventionally been provided. The liquid-absorbing cores are syntheticfibers such as polyester, polypropylene and acetate blended withheat-fusible fibers and formed into pillars, that lead chemicalsolutions contained in the containers to the mouths of the containersthrough capillary action. The chemical solutions lead to the mouths ofcontainers develop into fumes that diffuse to provide the environmentwith the effects of chemical agents.

[0003] In order to meet the increasing economic mind of consumers, thevolume tends to increase recently and absorption-type chemical agentvaporization apparatuses with containers that are larger and taller thanbefore are under development. When a conventional liquid-absorbing coreis used for this tall container, the chemical solution can be absorbedup and diffused to the environment without trouble during initial stageof use when the container is filled with the chemical solution up to thetop (high position). When the chemical solution is reduced after beingused for a while and left only at the bottom of the container, however,the force of absorption is not enough to lead the chemical solution upto the mouth of the container. Therefore, diffusion stops although thechemical solution is left, resulting in a problem that performance of alarge chemical solution diffusion apparatus cannot be fully exerted.

[0004] The present invention has been done in view of such a problem,and aims at providing a liquid-absorbing core that leads the chemicalsolution to the last drop up to the mouth of the container to diffuse iteven when a tall large container is used.

DISCLOSURE OF THE INVENTION

[0005] In order to solve the problems described above, the presentinvention provides a liquid-absorbing core comprising hydrophilic fiberand/or water-absorbing fiber.

[0006] The hydrophilic fiber used for the present invention is a fiberhaving affinity to water such as rayon, cotton and pulp. Rayon ispreferably used because of particularly high affinity to water and goodprocessability that enables easy formation of the liquid-absorbing corein the predetermined shape helped by its length.

[0007] Further, water-absorbing synthetic fibers such aspolyvinylalcohol and sodium polyacrylate, and other synthetic fiberstreated with polyvinylalcohol or sodium polyacrylate by adhesion orcoating can be mentioned as the water-absorbing fibers used for thepresent invention. As a commercial product, “Lanseal” (from Toyobo) canbe mentioned.

[0008] The liquid-absorbing core of the present invention may havevoidage of hydrophilic fiber and/or water-absorbing fiber of 10% to 80%.Voidage of over 80% leaves too large openings to absorb the chemicalsolutions high enough, and that of less than 10% reduces the amount ofthe chemical solution absorbed up and non-volatile ingredients (such assurfactants and dyes) fill the openings so that upward absorption of thechemical solutions may stop.

[0009] The liquid-absorbing core of the present invention can beobtained by simply bundling hydrophilic fiber and/or water-absorbingfiber, or by weaving them into threads or strings. Also, the bundles ofhydrophilic fiber and/or water-absorbing fiber can be rolled with filmsor tapes of polyethylene, polypropylene or cellophane to form pillars.

[0010] Further, the liquid-absorbing core of the present invention isformed by blending hydrophilic fiber and/or water-absorbing fiber withheat-fusible fiber and heat-fusing the same.

[0011] Polyethylene, polypropylene, low melting point polyester, andcore-sheath fiber of PET/PE can be mentioned as the heat-fusible fibersused for the present invention. Among them, low melting point polyesterwith a wide range of heat fusion temperature is preferably used in viewof heat-fusibility and productivity.

[0012] Conventionally known methods can be used for blending hydrophilicfiber and/or water-absorbing fiber with heat-fusible fiber. The blendedfibers can be molded into desired shapes by conventionally knownmethods. The ratio of blending of hydrophilic fiber and/orwater-absorbing fiber with heat-fusible fiber can be selected within theranges of 95% to 15% of the hydrophilic fiber and/or the water-absorbingfiber and 5% to 85% of the heat-fusible fiber. Less than 5% of theheat-fusible fiber causes difficulty in formation of theliquid-absorbing core, and over 85% of it reduces the effect of upwardabsorption of the liquid.

[0013] Further, the present invention provides a liquid-absorbing coremolded into pillars by gluing hydrophilic fiber and/or water-absorbingfiber with an adhesive. Polyurethane resin and epoxy resin can bementioned as the adhesive.

[0014] Also, another synthetic fiber can be blended in the presentinvention for the purpose of prevention of fuzz and improvement ofmoldability. Moldability here means reduction of frictional resistancewith the molding machine for improvement of smoothness of extrusion inextrusion molding of the liquid-absorbing core of the present invention.

[0015] Polyester and nylon can be mentioned as the synthetic fibers usedin the present invention. The ratio of the synthetic fiber to be blendedis up to 80% of the whole composition of the core. The ratio of over 80%prevents exertion of the effect of high absorption of the liquid eventhough smoothness of extrusion may be obtained.

[0016] The liquid-absorbing core of the present invention can be used inconventionally known absorption-type chemical agent diffusionapparatuses. In other words, the chemical solution is placed in acontainer equipped with an opening mouth, and a liquid-absorbing core ofthe present invention is positioned to reach from the mouth to thebottom of the container that leads the chemical solution in thecontainer to the mouth through a capillary action. The chemical solutionled to the mouth develops into volatile that volatilizes to provide theenvironment with effects of chemical agent.

[0017] Use of the liquid-absorbing core of the present invention in suchan absorption-type chemical agent diffusion apparatus enables theapparatus to lead the chemical solution to the above-mentioned moutheven when the amount of the chemical solution is reduced and thesolution is left only at the bottom of a tall container thatconventionally does not allow absorption of liquid to the top.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a schematic view of the absorption test method.

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] For explaining the present invention in more detail, explanationwill be made hereinbelow with reference to the accompanying drawings.The voidage described above is calculated by the following equation.$\begin{matrix}{{{Voidage}\quad (\%)} = {\frac{{\pi \quad r^{2} \times L} - \frac{g}{\rho}}{\pi \quad r^{2}L} \times 100}} & \left\lbrack {{Equation}\quad 1} \right\rbrack\end{matrix}$

[0020] r: radius of the liquid-absorbing core (cm)

[0021] L: length of the liquid-absorbing core (cm)

[0022] g: weight of the liquid-absorbing core (g)

[0023] ρ: specific gravity of the liquid-absorbing core (g/cm³)

ρ=ρ₁1+ρ₂2+ . . . ρ_(n) n

[0024] ρ_(1-31 n) density of fiber 1−n

[0025] 1−n: ratio of blending of fiber 1−n

EXAMPLE 1

[0026] Polyester 3 kg as a synthetic fiber, rayon 4 kg as waterabsorbing fiber, and low melting point polyester 3 kg were carded with acarding machine to obtain tops. Eight tops obtained were drawn severaltimes with a leveler to obtain slivers. The sliver thus obtained wassent through a cylindrical heater heated at 230 to 240° C. and thenthrough a cooling nozzle to obtain a 4φ thick liquid-absorbing core. Thevoidage of this liquid-absorbing core was 60%. The liquid-absorbing coreof this example thus obtained and cut to the length of 20 cm absorbed asolution of an aromatic substance up to the top when its lower end wasdipped in it.

EXAMPLE 2

[0027] Rayon fiber was weaved into strings to prepare a liquid-absorbingcore. The voidage of this liquid-absorbing core was 70%. Theliquid-absorbing core of this example thus obtained and cut to thelength of 20 cm absorbed a solution of an aromatic substance up to thetop when its lower end was dipped in it.

EXAMPLE 3

[0028] “Lanseal”, trade name, (a product of Toyobo) was carded with acarding machine to obtain tops. Four tops thus obtained were drawnseveral times with a leveler to obtain slivers. The slivers obtainedwere wound with polypropylene tape to prepare a pillar-shapedliquid-absorbing core. The voidage of the liquid-absorbing core was 30%.The liquid-absorbing core of this example thus obtained and cut tolength of 20 cm absorbed an aqueous solution of an aromatic substance upto the top, when its lower end was dipped in it.

EXAMPLE 4

[0029] Cotton 5 kg and polyester 5 kg were carded with a carding machineto obtain tops. Six tops thus obtained were drawn several times with aleveler to obtain slivers. The slivers obtained were dipped in apolyurethane adhesive bath, squeezed to get rid of excessive adhesive,and left standing to obtain a liquid-absorbing core. The voidage of theliquid-absorbing core was 20%. The liquid-absorbing core of this examplethus obtained and cut to length of 20 cm absorbed an aqueous solution ofan aromatic substance up to the top, when its lower end was dipped init.

EXAMPLE 5

[0030] Rayon was carded with a carding machine to obtain tops. Eighttops thus obtained were drawn several times with a leveler to obtainslivers. The slivers obtained were sent through a blow-molding machinefor polyethylene to inject polyethylene around the wall of the slivers.This was sent through a water bath for cooling to obtain a pillar-shapedliquid-absorbing core. The voidage of the liquid-absorbing core was 80%.The liquid-absorbing core of this example thus obtained and cut tolength of 20 cm absorbed an aqueous solution of an aromatic substance upto the top, when its lower end was dipped in it.

EXAMPLE 6

[0031] Pulp 5 kg and low melting point polyester 5 kg were thoroughlymixed and flattened to form a 10 cm thick sheet, that was sent through ahot roller heated at 230° C. to 240° C. to obtain a 1 cm thick sheet.The voidage of the sheet thus obtained was 30%. This sheet was cut intoa 1 cm wide by 20 cm long piece to obtain a square pillar-shapedliquid-absorbing core of the present invention. The liquid-absorbingcore of this example thus obtained absorbed an aqueous solution of anaromatic substance up to the top, when its lower end was dipped in it.

EXAMPLES 1-1 THROUGH 1-7)

[0032] Examples 1-1 through 1-7 and Comparative examples 1 and 2 areshown in Table 1 below. In Examples 1-1 through 1-7 and ComparativeExamples 1 and 2, liquid-absorbing cores were obtained in the samemanufacturing steps as in Example 1 described above, and with examplesof blending ratios (in % by weight) shown in Table 1 below. Voidages inthese Examples 1-1 through 1-7 and Comparative examples 1 and 2 were all60%.

[0033] Absorption tests were carried out with a configuration shown inFIG. 1. In other words, an aromatic deodorant solution 2 was placed upto 4 cm from the bottom of a container 1. A liquid-absorbing core 3 ofeach example 1-1 through 1-7 and comparative examples 1 and 2 was cut toa length of 20 cm, the lower end of each liquid-absorbing core wasinserted through the mouth into the container 1, and a 9 cm² wide filterpaper 4 was placed on its upper end. After being left standing for ahhour, infiltration of the aromatic deodorant solution 2 into the filterpaper 4 was observed visually. The absorption tests in which thearomatic deodorant solution 2 reached the filter paper 4 were given “◯”,and those in which the solution failed to reach the filter paper 4 weregiven “x”. Concerning “moldability”, the tests in which theliquid-absorbing cores could be formed in the same manufacturing stepsas in example 1 described above were given “◯”. TABLE 1 Example ExampleExample Example Example Example Example Comparative Comparative 1-1 1-21-3 1-4 1-5 1-6 1-7 example 1 example 2 Hydrophilic Rayon 15 95 15 30fiber Cotton 30 Water- Lanseal 30 absorbing fiber Polyvinylalcohol 30Heat-fusible Low melting point 85  5  5 50 40 40 40 40  5 fiberpolyethylene Synthetic PET 80 20 30 30 30 60 95 fiber Moldability ◯ ◯ ◯◯ ◯ ◯ ◯ ◯ ◯ Absorption ◯ ◯ ◯ ◯ ◯ ◯ ◯ x x

[0034] As seen in Table 1 shown above, Examples 1-1 through 1-5comprising rayon or cotton that are hydrophilic fibers and Examples 1-6and 1-7 comprising PVA-glued PET or polyvinylalcohol that arewater-absorbing fibers were given “◯” for both “moldability” and“absorption”. On the other hand, Comparative examples 1 and 2 withouthydrophilic fiber or water-absorbing fiber were given “x” for absorptionwhile they were given “◯” for moldability.

[0035] Thus, comprising hydrophilic fiber or water-absorbing fiber wasconfirmed to exert the effect of absorbing liquid high above.

EXAMPLES 1-8 AND 1-9

[0036] Examples 1-8 and 1-9 and comparative Example 3 are shown in Table2 below. In examples 1-8 and 1-9 and comparative example 3,liquid-absorbing cores were obtained in the same manufacturing steps asin Example 1 described above, and with examples of blending ratios (in %by weight) shown in Table 1 below. Voidage was calculated by the sameequation shown above and “absorption” was similarly evaluated using asimilar test apparatus as in Table 1 shown above. TABLE 2 ExampleExample Comparative 1-8 1-9 example 3 Hydrophilic fiber Rayon 30 30 —Heat-fusible fiber Low melting 30 30 40 point PET Synthetic fiber PET 4040 60 Voidage 10 80 10 Absorption ◯ ◯ x

[0037] As seen from Table 2 above, Examples 1-8 and 1-9 comprisinghydrophilic fiber, rayon, with voidage of 10% and 80% respectively weregiven “◯” for “absorption”. On the other hand, Comparative examples 1and 2 not comprising hydrophilic fiber or water-absorbing fiber weregiven “x” for “absorption” while they were given “◯” for “moldability”.

[0038] Thus, comprising rayon was confirmed to exert the effect ofabsorbing liquid high above. Voidage of 10% to 80% was also confirmed toexert the effect of absorbing liquid high above.

INDUSTRIAL APPLICABILITY

[0039] As explained above, the liquid-absorbing core of the presentinvention exerts the effect of absorbing liquid high above. Therefore,when an absorption-type chemical solution diffusion apparatus using acontainer that is larger and taller than conventional ones is used,sufficient absorption force can be secured to enable leading chemicalsolutions to the mouth of the container, even when only a small amountof the chemical solution is left as period of use passed, and thechemical solution is left only at the bottom of the container.Therefore, the chemical solution can be lead to the last drop up to themouth of the container to diffuse.

[0040] Also, good processability can be secured during molding by usingrayon, and further, fuzz of liquid-absorbing core can be prevented andmoldability can be improved by blending with synthetic fiber.

1. A liquid-absorbing core containing hydrophilic fiber and/orwater-absorbing fiber.
 2. A liquid-absorbing core containing hydrophilicfiber and/or water-absorbing fiber and having voidage of 10% to 80%. 3.A liquid-absorbing core being formed by blending hydrophilic fiberand/or water-absorbing fiber with heat-fusible fiber and heat-fusing thesame.
 4. A liquid-absorbing core formed by gluing hydrophilic fiberand/or water-absorbing fiber.
 5. The liquid-absorbing core according toany one of claims 1 to 4, wherein synthetic fiber is further blended. 6.A liquid-absorbing core containing rayon.
 7. A liquid-absorbing corecontaining rayon and having voidage of 10% to 80%.
 8. A liquid-absorbingcore formed by blending rayon with heat-fusible fiber and heat fusingthe same.
 9. A liquid-absorbing core formed by gluing rayon.
 10. Theliquid-absorbing core according to any one of claims 6 to 9, whereinsynthetic fiber is further blended.